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Purpose To evaluate the prevalence and risk factors for diabetic retinopathy (DR) in the Singapore Epidemiology of Eye Diseases (SEED) Study. Design Population-based, cross-sectional study. Participants Persons of Malay, Indian, and Chinese ethnicity aged 40+ years, living in Singapore. Methods Diabetes was defined as nonfasting plasma glucose ≥200 mg/dl (11.1 mmol/l), glycated hemoglobin A1c (HbA1c) >6.5%, self-reported physician-diagnosed diabetes, or the use of glucose-lowering medication. Retinal photographs, were graded for the presence and severity of DR using the modified Airlie House classification system. Main Outcome Measures Diabetic retinopathy, diabetic macular edema (DME), vision-threatening diabetic retinopathy (VTDR), defined as the presence of severe nonproliferative or proliferative DR, or clinically significant macular edema (CSME). Results Of the 10 033 subjects, 2877 (28.7%) had diabetes and gradable photographs for analysis. The overall age-standardized prevalence (95% confidence interval [CI]) was 28.2% (25.9–30.6) for any DR, 7.6% (6.5–9.0) for DME, and 7.7% (6.6–9.0) for VTDR. Indians had a higher prevalence of any DR (30.7% vs. 26.2% in Chinese and 25.5% in Malays, P = 0.012); a similar trend was noted for any DME ( P = 0.001) and CSME ( P = 0.032). Independent risk factors for any DR were Indian ethnicity (odds ratio [OR], 1.41; 95% CI, 1.09–1.83, vs. Chinese), diabetes duration (OR, 1.10; 95% CI, 1.08–1.11, per year), HbA1c (OR, 1.25; 95% CI, 1.18–1.32, per %), serum glucose (OR, 1.03; 95% CI, 1.00–1.06, per mmol/l), and systolic blood pressure (OR, 1.14; 95% CI, 1.09–1.19, per 10 mmHg). Diastolic blood pressure (OR, 0.74; 95% CI, 0.65–0.84, per 10 mmHg increase), total cholesterol (OR, 0.87; 95% CI, 0.80–0.95, per mmol/l increase), and low-density lipoprotein (LDL) cholesterol (OR, 0.83; 95% CI, 0.74–0.92, per mmol/l increase) were associated with lower odds of any DR. Risk factors were largely similar across the 3 ethnic groups. Conclusions Indian Singaporeans have a higher prevalence of DR and DME compared with Chinese and Malays. Major risk factors for DR in this study were similar across the 3 ethnic groups. Addressing these risk factors may reduce the impact of DR in Asia, regardless of ethnicity.

Purpose To determine the 6-year incidence of early and late age-related macular degeneration (AMD) in a Singaporean Malay population and to validate the Age-Related Eye Disease Study (AREDS) simplified severity scale in Asians. Design Prospective, population cohort study. Participants The Singapore Malay Eye Study baseline participants (age, ≥40 years; 2006–2008) were followed up in 2011 through 2013, and 1901 of 3280 of eligible participants (72.1%) took part. Methods Fundus photographs were graded using the Wisconsin AMD grading system. Main Outcome Measures Incidence of early and late AMD. Results Gradable fundus photographs were available for 1809 participants who attended both baseline and 6-year follow-up examinations. The age-standardized incidences of early and late AMD were 5.89% (95% confidence interval [CI], 4.81–7.16) and 0.76% (95% CI, 0.42–1.29), respectively. The 5-year age-standardized incidence of early AMD (calculated based on the 6-year incidence) was lower in our population (5.58%; 95% CI, 4.43–7.01) compared with the Beaver Dam Eye Study population (8.19%). The incidence of late AMD in our population was similar to that of the Beaver Dam Eye Study population (0.98% [95% CI, 0.49–1.86] vs. 0.91%), the Blue Mountains Eye Study population (1.10% [95% CI, 0.52–9.56] vs. 1.10%), and the Hisayama Study population (1.09% [95% CI, 0.54–4.25] vs. 0.84%). The incidence of late AMD increased markedly with increasing baseline AREDS score (step 0, 0.23%; step 4, 9.09%). Conclusions This study documented the incidence of early and late AMD in a Malay population. The AREDS simplified severity scale is useful in predicting the risk of late AMD development in Asians.

Micro heat exchangers are the integral part of advanced technologies such as space technologies. However, the cooling of these micro heat exchangers encounters various challenges due to large aspect ratios. Further, the conventional coolants could not dissipate the heat due to limited thermal conductivity and specific heat. Hence, suspension of nanoparticles in such coolants would increase the efficiency of micro heat exchanges. Nanofluids are widely used in biomedical applications, as coolants in transportation, industrial cooling, nuclear reactor cooling and defense applications due to their higher stability, higher heat transfer capabilities and reduced particle clogging. In the present work, the thermophysical properties of Al2O3, SiO2, SiC, CuO and TiO2 nanoparticles in Liquid Nitrogen (LN2) are studied with the volume concentration of 3%. It is observed that thermal conductivity of nanofluid is enhancing with the increase in volume concentration of nanoparticles which result in enhancing the heat transfer rate in micro heat exchangers. In order to confirm this fact, a computational investigation on pressure drop and heat transfer is performed with Liquid Nitrogen as a base fluid and CuO, SiO2, SiC, Al2O3 and TiO2 as nanoparticles. A computational geometry is developed in ANSYS® and the pressure drop and heat transfer analysis is done using FLUENT®. Relevant boundary conditions are applied to reflect the practical operating conditions of micro heat exchangers. It is observed from the results that the decrease in pressures drop with the suspension of CuO nanoparticle is low. Further, the heat transfer is observed to be increasing with the addition of Al2O3 and SiO2 nanoparticles with the concentration of 3% by volume. Finally, it can be concluded that the dispersion of the nanoparticles in Liquid Nitrogen (LN2) is beneficial to be used in micro heat exchangers.

The impact of grain hardness on iron bioavailability from a set of wheat genotypes with varying hardness indices was determined. This may help us to consider grain hardness as an important parameter along with other established parameters for selecting food crops for future biofortification programs to combat iron deficiency linked to global health problem. The bioavailability and dialysability of iron were determined using the coupled in vitro digestion/Caco-2 model. The grain hardness and its molecular basis along with grain iron, phytate and inorganic phosphorous (Pi) contents were also evaluated. The data indicated that iron concentration in the genotypes ranged from 21 to 50 μg/g of dry matter. The hardness indices varied from as low as 28 for the derivative BTC17 to as high as 92 for the landrace IITR 26, almost similar to that of WL711, a wild type cultivar considered as control in this study. Low variability was however observed for the phytate and Pi contents. A significant negative correlation was observed between grain hardness vs. dialysability ( r = −0.73) and bioavailability ( r = −0.75) of iron. The results suggest that the hardness index which profoundly affects milling process, particle size of flour, milling yield and end-use also influences dialysability and bioavailability of iron from wheat.

The zinc bioavailability from wheat- Aegilops derivatives and Triticum monococcum low phytic acid ( lpa ) mutants with varying zinc concentrations was assessed using a novel metal response element (MRE)-binding transcription factor-1 (MTF-1)/MRE luciferase reporter gene based transactivation assay in the coupled in vitro digestion/Caco-2 model. The zinc content in the genotypes studied ranged from 19 to 65 μg/g. The bioavailability enhancement of zinc as determined from the luciferase response of MTF1/MRE transfected cells to cooked digests of biofortified derivatives and the lpa mutants was recorded as a 1.2–2.0 fold-increase, corresponding to 1.8–3.3 fold increases in the zinc content over the respective WL711-cultivar and T. monococcum wild-type controls. The strong positive and negative correlations observed for zinc bioavailability with respect to zinc content and phytate:zinc molar ratios in the derivatives ( r = 0.74 and −0.76) as well as lpa mutants ( r = 0.89 and −0.94) illustrate the significance of using these parameters in zinc biofortification programmes. Genotypes with phytate:zinc molar ratios of less than 15, with remarkably enhanced zinc bioavailability, were identified. This method could thus serve as a sensitive transactivation assay for a screening approach that could accurately rank bioavailability of zinc from biofortified staples for subsequent animal studies and advance select lines for human studies.

Age-related macular degeneration (AMD), the late stage of age-related maculopathy (ARM), is the leading cause of blind registration in developed countries. The visual loss in AMD occurs due to dysfunction and death of photoreceptors (rods and cones) secondary to an atrophic or a neovascular event. The psychophysical tests of vision, which depend on the functional status of the photoreceptors, may detect subtle alterations in the macula before morphological fundus changes are apparent ophthalmoscopically, and before traditional measures of visual acuity exhibit deterioration, and may be a useful tool for assessing and monitoring patients with ARM. Furthermore, worsening of these visual functions over time may reflect disease progression, and some of these, alone or in combination with other parameters, may act as a prognostic indicator for identifying eyes at risk for developing neovascular AMD. Lastly, psychophysical tests often correlate with subjective and relatively undefined symptoms in patients with early ARM, and may reflect limitation of daily activities for ARM patients. However, clinical studies investigating psychophysical function have largely been cross-sectional in nature, with small sample sizes, and lack consistency in terms of the grading and classification of ARM. This article aims to comprehensively review the literature germane to psychophysical tests in ARM, and to furnish the reader with an insight into this complex area of research.